CN112564420B

CN112564420B - Large-load high-speed motor bearing cooling device

Info

Publication number: CN112564420B
Application number: CN202011364672.2A
Authority: CN
Inventors: 王礼恒; 胡良兵; 庄明
Original assignee: Hefei Institutes of Physical Science of CAS
Current assignee: Hefei Institutes of Physical Science of CAS
Priority date: 2020-11-27
Filing date: 2020-11-27
Publication date: 2022-02-11
Anticipated expiration: 2040-11-27
Also published as: CN112564420A

Abstract

The invention provides a large-load high-speed motor bearing cooling device, which comprises an end cover with a grease injection hole, a cover plate, a bearing pressing plate, an outer bearing bracket, a bearing limiting ring and a bearing bush, wherein the bearing pressing plate is provided with a grease injection hole; wherein, an outer bearing bracket is arranged between the end cover and the bearing; bearings are respectively arranged on two sides of the outer bearing bracket; the end cover is provided with a grease injection hole for injecting lubricating grease, the lubricating grease can respectively flow to the bearings on the two sides through the outer bearing support, and the lubricating grease can not flow to the outside of the end cover through the blocking of the end cover and the bearing pressing plate; when the lubricating grease in the bearing is lost, the lubricating grease in the grease injection hole of the end cover can be automatically supplemented under the action of gravity; a set screw is arranged in a grease injection hole on the surface of the end cover; the outer bearing support is annular, the annular end faces on the two sides are provided with grooves which are arranged in a staggered mode, and lubricating grease is guided to smoothly flow to the bearings on the two sides through the grooves which are arranged in the staggered mode on the two ends.

Description

Large-load high-speed motor bearing cooling device

Technical Field

The invention relates to the field of motors, in particular to a large-load high-speed motor bearing cooling device.

Background

Prior to the present invention, the bearings commonly used for high speed motors (>20000rpm) were air bearings, oil-air lubricated bearings and magnetic bearings: the air bearing uses gas as a lubricant, is high temperature resistant and pollution-free, but has lower load capacity; the oil-gas lubrication is realized by continuously inputting lubricating and cooling oil gas to the bearing through an external gas supply device, and the oil-gas lubrication is difficult to apply in some environments requiring closed vacuum, and simultaneously, the complexity and the space requirement of a system are increased due to the need of the external gas supply device; the magnetic suspension bearing suspends a rotor in the air by utilizing the magnetic force, has small mechanical abrasion, does not need lubrication and has no oil pollution, but has high manufacturing cost, is often used together with other types of bearings, and has very complicated control system.

Meanwhile, the frequency of the high-speed motor is linearly increased along with the rotating speed and the number of pole pairs of the motor, and the frequency increase can cause the increase of the loss of a motor iron core to cause the reduction of the efficiency of the motor and the increase of heating temperature and challenge the switching frequency of electronic power components of a control system, so that the high-speed motor uses fewer pole pairs as far as possible, and the minimum 1 pair of poles is the best: for a small-load high-speed motor (below 45 kW), a large size is not required, and as long as the outer diameter of a rotor of the motor is smaller than the size (phi 100mm) met by the current process, the tile-type radial radiation ring magnetized permanent magnet is adopted to be attached to the rotor, so that the requirement that the motor has the smallest number of pole pairs as possible is met, and the frequency of the high-speed motor is reduced; however, for a high-speed motor requiring large-load application, namely a large-size space is required, once the outer diameter of a rotor is larger than a certain size, a scheme of surface-mounting a tile permanent magnet for radial ring type magnetization is difficult to realize technically, so that most of the high-speed large-load motors currently use a scheme of embedding permanent magnets in 2 pairs of poles or more, so that the motors have the difficulties of increasing the rotating speed, increasing the efficiency and lowering the system cost.

Disclosure of Invention

The invention mainly aims to design a large-load high-speed motor bearing cooling device, which relates to the lubrication and cooling of a motor bearing and the design of small pole pair number of a rotor. According to the invention, the grease-lubricated bearing is used as a high-speed motor bearing, and the problems that the temperature of the grease-lubricated bearing rises fast during high-speed operation and the service life of the motor is short due to large grease loss are solved through the convenient bearing grease injection and bearing cooling device, so that the heat generation of the motor bearing is effectively reduced, and the service life of the motor is prolonged; the scheme of using the rotor surface-mounted parallel magnetizing tile-shaped permanent magnet is adjusted and used through the optimized design of the motor magnetic field, so that the problems of high frequency, high loss, high heating efficiency and low efficiency caused by the fact that the large-load motor cannot use the surface-mounted radial ring magnetizing tile-shaped permanent magnet due to the fact that the large rotor diameter cannot realize small pole pairs are effectively solved. The invention is suitable for the motor with large load and high rotating speed.

A large-load high-speed motor bearing cooling device comprises an end cover with a grease injection hole, a cover plate, a bearing pressing plate, an outer bearing support, a bearing limiting ring and a bearing bush; wherein the content of the first and second substances,

an outer bearing bracket is arranged between the end cover and the bearing; bearings are respectively arranged on two sides of the outer bearing bracket;

the end cover is provided with a grease injection hole for injecting lubricating grease, the lubricating grease can respectively flow to the bearings on the two sides through the outer bearing support, and the lubricating grease can not flow to the outside of the end cover through the blocking of the end cover and the bearing pressing plate; when the lubricating grease in the bearing is lost, the lubricating grease in the grease injection hole of the end cover can be automatically supplemented under the action of gravity;

a set screw is arranged in a grease injection hole on the surface of the end cover;

the outer bearing support is annular, the annular end faces on the two sides are provided with grooves which are arranged in a staggered mode, and lubricating grease is guided to smoothly flow to the bearings on the two sides through the grooves which are arranged in the staggered mode on the two ends.

Further, a cooling flow passage is formed in the end cover, and is connected in series with the cooling flow passage of the motor main housing through the first opening and the second opening, so that the cooling liquid of the motor main housing is introduced into the end cover and is cooled through the cooling flow passage to form a bearing chamber, thereby reducing the temperature of the bearing.

Furthermore, an independent cooling liquid inlet and outlet is additionally arranged between the first opening and the second opening of the cooling flow channel formed in the end cover and connected with the cooling flow channel of the main shell of the motor in parallel, so that the parallel bearing cooling flow channel can be opened at any time when the cooling liquid of the main shell connected with the bearing cooling flow channel in series is in fault due to insufficient pressure and blockage or when the flow of the cooling liquid of the bearing needs to be increased to enhance the cooling and heat dissipation of the bearing.

Furthermore, a plurality of bosses are arranged in a cooling flow passage of the end cover and are matched with the flow passage cover plate to form an S-shaped flow passage, and the bearing is cooled simultaneously.

Furthermore, the rotor is supported and fixed by a rotating shaft with an iron core or an integrated rotating shaft, the surface-mounted parallel magnetizing tile-shaped permanent magnets are pasted and fixed on the rotating shaft, the N or S permanent magnets with the same polarity are formed by integral molding or block splicing and bonding, the N and S permanent magnets with different polarities are fixed on the rotating shaft at intervals by non-magnetic-conductive materials for reducing magnetic leakage, all the permanent magnets are axially fixed on the rotating shaft through a front shaft sleeve and a rear shaft sleeve, the front shaft sleeve and the rear shaft sleeve are used for dynamic balance weight removal or weight addition, and finally, a high-speed high-temperature-resistant carbon fiber protective ring is embedded outside the whole rotor with high-speed stress intensity.

Further, a set screw is installed in a grease injection hole on the surface of the end cover and is used for being unscrewed periodically to check the loss condition of the lubricating grease and replenishing the lubricating grease at any time according to the requirement.

The invention has the advantages that:

1. the bearing cooling device uses the grease lubrication bearing to replace an air bearing, so that the problem that the high-speed motor cannot be applied to a heavy-load scene when the air bearing is used is solved;

2. the bearing cooling device uses the grease lubrication bearing to replace an oil-gas lubrication bearing, so that the problem that the requirement for using the oil-gas lubrication bearing in a closed vacuum environment cannot be met when a high-speed motor uses the oil-gas lubrication bearing is solved, and the complexity and the cost of a system are reduced;

3. the bearing cooling device of the invention uses the grease lubrication bearing to replace the magnetic suspension bearing, thus solving the problem of high price of the magnetic suspension bearing and effectively reducing the overall cost of the heavy-load high-speed motor and the control system thereof;

4. the bearing cooling device effectively solves the problems of bearing temperature rise and high lubricating grease loss of the grease lubrication bearing in the application scene of a large-load high-speed motor;

5. the bearing cooling device of the invention uses the bearing cooling flow channel connected in series and parallel with the motor main shell cooling flow channel to ensure the cooling of the bearing and a convenient lubricating grease supplement and detection method, thereby effectively prolonging the service life of the bearing and further improving the reliability of the motor;

6. the bearing cooling device effectively solves the problems of high frequency, high loss, high heat generation, low efficiency and high cost of a motor control system caused by the fact that a large-load (power of more than 45 kW) motor needs a large-diameter rotor and needs a multi-pair-pole embedded permanent magnet rotor under the condition that the scheme of surface-mounted radial ring magnetizing tile-shaped permanent magnet cannot be used due to the fact that a small-pole-pair surface-mounted parallel magnetizing tile-shaped permanent magnet scheme is adopted.

Drawings

FIG. 1 is a schematic cross-sectional view of a bearing grease injection flow passage;

FIG. 2 is a schematic diagram of the staggered arrangement of the grooves of the outer bearing support;

FIG. 3 is a schematic cross-sectional view of a bearing cooling flow path;

FIG. 4 is a schematic view of a boss for increasing heat dissipation area in a bearing cooling flow passage;

FIG. 5 is a schematic view of the bearing cooling "S" flow path development;

fig. 6 is a schematic diagram of a scheme of pasting parallel magnetizing tile-shaped permanent magnets on opposite pole surfaces of a rotor 1.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments, and all other embodiments obtained by a person skilled in the art based on the embodiments of the present invention belong to the protection scope of the present invention without creative efforts.

According to one embodiment of the invention, a large-load high-speed motor bearing cooling device and a method are provided, wherein the device comprises an end cover with a grease injection hole, a cover plate, a bearing pressure plate, an outer bearing bracket, a bearing limiting ring, a bearing bush and the like.

An outer bearing bracket (104) is arranged between the outer end cover and the bearing (102);

referring to fig. 1 and 3, a grease injection hole is formed in the end cap (101) for fast injection of grease, and the grease flows to the bearings (102) on both sides through the outer bearing support (104) and is blocked by the end cap (101) and the bearing pressure plate (103) so that the grease does not flow to the outside.

When the grease in the bearing is lost, the grease in the hole of the end cover (101) can be automatically replenished under the action of gravity.

As shown in fig. 1, a set screw (105) is mounted on the upper surface of the end cap (101) and is used for periodically unscrewing to check the grease loss condition and replenishing the grease at any time according to the requirement.

Outer bearing support (104) are the annular, are provided with staggered arrangement's recess at both sides annular end face, through the recess of both ends staggered arrangement, when guaranteeing to support intensity, guide the bearing on flow direction both sides that lubricating grease can be smooth and easy. (FIG. 2)

A cooling flow passage (106) is formed in the end cover (101), and is connected with the cooling flow passage of the main shell of the motor in series through a first opening (107) and a second opening (108), so that cooling liquid of the main shell of the motor is introduced into the end cover (101) and is cooled through the cooling flow passage (106) to form a bearing chamber, and the temperature of the bearing (102) is reduced.

Referring to fig. 3, an independent cooling liquid inlet and outlet is additionally added above a first opening (107) and a second opening (108) of a cooling flow channel (106) formed in an end cover (101) and is connected in parallel with the cooling flow channel of the main shell of the motor, so that the parallel bearing cooling flow channel is opened at any time when the main shell cooling liquid connected in series with the bearing cooling flow channel (106) fails due to insufficient pressure, blockage and the like or when the bearing cooling heat dissipation needs to be enhanced by increasing the flow of the bearing cooling liquid. (FIG. 3)

Be equipped with a plurality of bosss (109) in the cooling channel of end cover (101), also be provided with crisscross boss on runner apron (110), be equipped with a plurality of bosss (109) in the cooling channel and form "S" shape runner with runner apron (110) cooperation, increase heat radiating area to cool off bearing (102) simultaneously, guarantee that the temperature of bearing (102) can not appear big difference, guaranteed the stability of motor operation. (FIG. 4, FIG. 5)

According to one embodiment of the invention, the rotor is supported and fixed by a rotating shaft with a iron core or an integrated rotating shaft (111), the surface-mounted parallel magnetized tile-shaped permanent magnet (113) is fixed on the rotating shaft (111) through high-strength AB glue, such as Letai E-120HP, the N or S permanent magnet (113) with the same polarity can be integrally formed or spliced and adhered in blocks, the N and S permanent magnets (113) with different polarities can be fixed on the rotating shaft at intervals by non-magnetic-conductive materials (115) for reducing magnetic leakage, all the permanent magnets (113) are axially fixed on the rotating shaft (111) through a front shaft sleeve and a rear shaft sleeve (114), the front shaft sleeve and the rear shaft sleeve (114) can also be used for dynamic balance de-weighting or weighting, and finally, a high-speed high-temperature-resistant carbon fiber protective ring (112) is embedded outside the whole high-speed stress strength rotor. (FIG. 6)

The device meets the application of a high-speed motor in a heavy-load scene and reduces the complexity and the cost of the system through bearing lubricating grease injection and a bearing cooling device.

Through the design of grease injection and guide flow passages, the requirement of random supplement and correct flow direction after the loss of the bearing lubricating grease is met, and the bearing is lubricated.

Through the series-parallel connection design of the bearing cooling flow channel and the motor main shell flow channel, the risk of bearing damage when the main shell cooling liquid connected with the bearing cooling flow channel in series fails due to insufficient pressure, blockage and the like or the bearing cooling heat dissipation cannot be realized by increasing the flow of the bearing cooling liquid.

Through the scheme of the minimum pole pair number surface-mounted parallel magnetizing tile-shaped permanent magnet capable of reaching 1 pair of poles, the application of the high-speed motor in a heavy-load scene is met, the rotating speed can be increased, the efficiency can be increased, the temperature rise can be reduced, and the cost of the motor and the system thereof can be reduced.

Although illustrative embodiments of the present invention have been described above to facilitate the understanding of the present invention by those skilled in the art, it should be understood that the present invention is not limited to the scope of the embodiments, but various changes may be apparent to those skilled in the art, and it is intended that all inventive concepts utilizing the inventive concepts set forth herein be protected without departing from the spirit and scope of the present invention as defined and limited by the appended claims.

Claims

1. A large-load high-speed motor bearing cooling device is characterized by comprising an end cover with a grease injection hole, a flow passage cover plate, a bearing pressing plate, an outer bearing support, a bearing limiting ring and a bearing bush; wherein the content of the first and second substances,

an outer bearing support (104) is arranged between the end cover and the bearing (102); bearings (102) are respectively arranged on two sides of the outer bearing bracket (104);

a grease injection hole is formed in the end cover (101) and used for injecting grease, the grease can flow to the bearings (102) on two sides through the outer bearing support (104), and the grease cannot flow to the outside of the end cover through the blocking of the end cover (101) and the bearing pressing plate (103); when the lubricating grease in the bearing is lost, the lubricating grease in the grease injection hole of the end cover (101) can be automatically supplemented under the action of gravity; an independent cooling liquid inlet and outlet is additionally arranged between a first opening (107) and a second opening (108) of a cooling flow channel (106) formed in an end cover (101) and is connected with the cooling flow channel of the main shell of the motor in parallel, and the parallel bearing cooling flow channel is opened at any time when the cooling flow channel of the main shell connected with the bearing cooling flow channel (106) in series is blocked due to insufficient pressure or the flow of the bearing cooling liquid needs to be increased to enhance the cooling and heat dissipation of the bearing;

a set screw (105) is arranged in a grease injection hole on the surface of the end cover (101);

the outer bearing support (104) is annular, the annular end faces on the two sides are provided with grooves which are arranged in a staggered mode, and lubricating grease can be guided to smoothly flow to the bearings on the two sides through the grooves which are arranged in the staggered mode on the two ends.

2. A large-load high-speed motor bearing cooling device as claimed in claim 1, wherein a cooling flow passage (106) is formed in the end cover (101), and is connected in series with the cooling flow passage of the motor main housing through the first opening (107) and the second opening (108), and the cooling fluid of the motor main housing is introduced into the end cover (101) and cooled through the cooling flow passage (106) to cool the bearing chamber, thereby reducing the temperature of the bearing (102).

3. A large-load high-speed motor bearing cooling device as claimed in claim 1, wherein a plurality of bosses (109) are provided in the cooling flow passage of the end cover (101), and cooperate with the flow passage cover plate (110) to form an S-shaped flow passage and cool the bearing (102) at the same time.

4. A large-load high-speed motor bearing cooling device as claimed in claim 1,

a surface-mounted parallel magnetizing tile-shaped permanent magnet (113) with 1 pair of poles is adopted and is stuck and fixed on a rotating shaft (111).

5. The cooling device for the large-load high-speed motor bearing according to claim 1, wherein the rotor is supported and fixed by a rotating shaft with a core or an integrated rotating shaft (111), surface-mounted parallel magnetized tile-shaped permanent magnets (113) are adhered and fixed on the rotating shaft (111), N or S permanent magnets (113) with the same polarity are formed by integral molding or splicing and bonding in blocks, in order to reduce magnetic leakage and fix the N and S permanent magnets (113) with different polarities on the rotating shaft at intervals by non-magnetic-conductive materials (115), all the permanent magnets (113) are axially fixed on the rotating shaft (111) through a front shaft sleeve and a rear shaft sleeve (114), the front shaft sleeve and the rear shaft sleeve (114) are used for dynamic balance de-weighting or weighting, and finally, a high-speed high-temperature-resistant carbon fiber protective ring (112) is embedded outside the whole rotor with high-speed stress intensity.

6. A heavy duty high speed motor bearing cooling arrangement as claimed in claim 1 wherein said grease injection holes in the end cap (101) surface are fitted with set screws (105) for periodic unscrewing to check for grease loss and replenishment as required at any time.